The invention relates to monoazo compounds containing sulphonic acid groups, salts thereof and mixtures of these compounds. They are suitable for use as dyestuffs.
According to the invention there are provided compounds of formula (I): 
wherein
D is the rest of a diazo component selected from the group having the formulae (a), (b), (c) 
A is OH or NH2;
R1 is independently H, C1-4alkyl;
R2 is hydrogen, C1-4alkyl, C1-4alkoxy, halogen;
X is an aliphatic, cycloaliphatic, aromatic or heterocyclic amino group;
Y is a divalent bridge;
m is 0, 1 or 2; and
n is 1 or 2;
and salts thereof as well as mixtures of such compounds.
Preferred compounds of formula (I) have the formulae (Ia), (Ib) or (Ic): 
wherein R1, R2, X, Y and A have the meaning given above; in metal-free or copper complex form, and salts thereof and mixtures of such compounds or complexes. Preferably the compounds of formula (Ia) above, are in metal-free form. 
wherein R1, R2, m, n, X and Y have the meaning given above; 
wherein R1, R2, X and Y have the meaning given above; salts thereof and mixtures of such compounds.
Preferably the sulphonic acid groups on the naphtholrest are attached at the 3- and 6-positions of the naphthol radical.
Any alkyl or alkylene present is linear or branched unless indicated to the contrary. In any hydroxy- or alkoxy-substituted alkyl or alkylene group which is linked to a nitrogen atom, the hydroxy or alkoxy group is bound to a carbon atom other than to the C1-atom. In any alkylene group substituted by two hydroxy groups, the hydroxy groups are bound to different carbon atoms.
Halogen atoms are preferably chlorine.
X is preferably amino, mono- or di-C1-3alkylamino, mono- or di(hydroxy-C2-4alkyl)amino, monocarboxy-C1-4alkylamino, monosulpho-C1-4alkylamino, optionally substituted phenylamino, phenylalkylamino, morpholino or piperazino (substituted by alkyl or hydroxyalkyl).
Y is a divalent bridge linking two parts of the molecule via nitrogen atoms attached to the triazine ring and preferably is the rest of phenylene diamine, piperazine or 4,4xe2x80x2-diaminostilbene-2,2xe2x80x2-disulfonic acid.
Any alkyl as R1 preferably contains 1 or 2 carbon atoms, and is more preferably methyl. Any substituted alkyl is preferably linear or branched C2-3alkyl, and is preferably monosubstituted by hydroxy.
R2 is preferably hydrogen or C1-4alkyl, most preferably methyl.
The present invention further provides a process for the preparation of compounds of formula (I) comprising reacting the dyestuff of formula (IIa) having the following formula: 
in which R1 is as above defined and Hal is halogen, with a diazotised compound of formula (IIb), having the following formula:
Dxe2x80x94NH2xe2x80x83xe2x80x83(IIb)
so as to give a compound of formula (III), having the following formula: 
in which D and R1 are as above defined, which compound is reacted with an appropriate diamino compound to give a compound of formula (I) in which X is halogen.
Finally, such compound is further reacted with an appropriate amino compound to give a compound of formula (I) in which X is an amino group. If mixtures are intended, the starting compounds are reacted as mixtures or the final compounds are mixed.
An alternative process for the preparation of compounds of formula (I), in which D is of formula (a) with A=OH and/or formula (c), comprises reacting the dyestuff of formula (IV) having the following formula: 
in which D and R1 are as above defined and preferably the substituents being so positioned as above defined, with cyanuric halogenide so as to give a compound of formula (III), having the following formula: 
in which D and R1 are as above defined, which compound is reacted with an appropriate diamino compound to give a compound of formula (I) in which X is halogen. Finally, such compound is further reacted with an appropriate amino compound to give a compound of formula (I) in which X is an amino group.
A metal-free compound of formula (I) in which D is of the formula (a) with COOH may be converted into a 1:1 copper complex in accordance with known methods. This coppering may be carried out by reacting an appropriate metal-free compound of formula (I) with a copper-donating compound which is employed in such an amount so as to provide at least one equivalent of copper per equivalent of monoazo compound to be metallised.
Suitably, the 1:1 copper complexes may be prepared at 10xc2x0 C. to 50xc2x0 C. and at pH 4 to 7 in the presence of copper(II) salts.
The compounds of formula (I) thus obtained may be isolated in accordance with known methods.
The type of cations assigned to the sulpho groups in a compound of formula (I) may be influenced in various ways in accordance with the process; these are known methods throughout. In particular, mixed salts may be obtained by well-directed control of the process employed.
The compounds according to the invention in the form of their water-soluble salts are used for dyeing or printing organic substrates containing hydroxy groups, thiol groups or nitrogen, in particular as paper dyes or direct dyes.
As a result of their high substantivity, the compounds according to the invention are very suitable as direct dyes. The usual technical application processes are employed as dyeing and printing processes. Natural and regenerated cellulose, e.g. cotton, are preferably dyed by a conventional exhaust process at dyeing temperatures of 50-100xc2x0 C.
The dyestuffs according to the invention are notable for their depth of color, and produce good exhaust. The dyeings obtained (especially on cotton and paper) are of pure shade.
On the said substrates, the dyeings generally have very good wet fastnesses and good light fastness. The very good water and perspiration fastness and good fastness to peroxide, perborate and chlorine may also be mentioned.
The wet fastness of the direct dyeings on cellulosic textile materials may be decisively improved by means of a special after-treatment with selected assistants. In particular, the washing fastness is improved such that its quality level does not undergo any reduction even after repeated washes at 60xc2x0 C.
A suitable assistant for this after-treatment may be a fixing agent in the form of a pre-condensate or mixture, which is obtained either
A) from the product of reacting the mono- or poly-functional primary or secondary amine with cyanamide, dicyandiamide, guanidine or biguanide; or of ammonia with cyanamide or dicyandiamide, whereby the product contains reactive hydrogen atoms bonded to nitrogen, or
B) from a quaternary polyalkylene-polyamine with
C) a N-methylol compound of a urea, melamine, guanamine, triazinone, urone, carbamate or acid diamide, optionally in the presence of
D) a catalyst for cross-linking with a N-methylol compound of type C.
Details relating to the assistant in the form of the combination A/C/D are described in detail in PCT application publication no. WO 81/02 423; details on the combination B/C/D may be found in German Published Specification DOS 31 37 404.
Printing is effected by means of impregnation with a printing paste which is prepared by a known method.
The new dyestuffs may also be used for dyeing or printing leather, preferably chrome-tanned types of leather, using methods known per se. In addition, the dyestuffs may be used to produce inks by a method known per se.
Most preferably, the dyestuffs are used for dyeing or printing of paper e.g., sized or unsized, wood-free or wood-containing paper or paper-based products such as cardboard. They may be used in continuous dyeing in the stock, dyeing in the size press, in a conventional dipping or surface coloring process. The dyeing and printing of paper is effected by known methods.
The dyeings and prints and particularly those obtained on paper, show good fastness properties.
The compounds of formula (I) may be converted into dyeing preparations. Processing into stable liquid, preferably aqueous, or solid (granulated or powder form) dyeing preparations may take place in a generally known manner. Advantageously suitable liquid dyeing preparations may be made by dissolving the dyestuff in suitable solvents such as mineral acids or organic acids, e.g., hydrochloric acid, sulphuric acid, phosphoric acid, formic acid, acetic acid, lactic acid, glycolic acid, citric acid and methanesulphonic acid. Furthermore formamnide, dimethylformamide, urea, glycols and ethers thereof, dextrin or addition products of boric acid with sorbite may be used together with water, optionally adding an assistant, e.g. a stabilizer. Such preparations may be obtained, for example, as described in French patent specification No. 1,572,030.
The compounds of formula (I) (in the corresponding salt form) have good solubility especially in cold water. Owing to their high substantivity the compounds of the present invention exhaust practically quantitatively and show a good build-up power. They can be added to the stock directly, i.e. without previously dissolving, as either a dry powder or granulate, without reducing the brilliance or the yield of color. They can also be used in soft water without loss of yield. They do not mottle when applied on paper, are not inclined to give two-sided dyeing on paper and are practically insensitive to filler or pH variations. They operate over a broad pH range, in the range of from pH 3 to 10. When producing sized or unsized paper, the waste water is essentially colorless. This feature, which is extremely important from an environmental view-point, when compared with similar known dyes, shows a marked improvement. A sized paper dyeing when compared with the corresponding unsized paper dyeing does not show any decrease in strength.
The paper dyeings or printings made with the compounds, in particular the metal-free forms, according to the invention are clear and brilliant and have good light fastness: On exposure to light for a long time, the shade of the dyeing fades tone in tone. They show very good wet fastness properties; being fast to water, milk, fruit juice, sweetened mineral water, tonic water, soap and sodium chloride solution, urine etc. Furthermore, they have good alcohol fastness properties. The wet fastness properties are improved compared to known dyes showing otherwise similar properties. They do not exhibit a tendency towards two-sidedness.
Paper dyed or printed with the compounds of the present invention can be bleached either oxidatively or reductively, a feature which is important for the recycling of waste and old paper/paper products. It has surprisingly been found that the dyes of the present invention demonstrate excellent bleachability, particularly when bleaching is carried out reductively. This property, together with the improved backwater results and wet-fastnesses, shows a marked improvement over known dyes having otherwise similar properties.
The compounds of the present invention may also be used to dye paper containing wood-pulp where even dyeings, having good fastness properties are obtained. Furthermore, they may be used for the production of coated paper in accordance with known methods. Preferably when coating, a suitable filler, for example kaolin, is employed in order to give a one-side coated paper.
The compounds of the present invention are also suitable for dyeing in combination with other dyes for example other cationic or anionic dyes. The compatibility of the compounds of the present invention when used as a dye in mixtures with other commercially available dyes, may be determined according to conventional methods. The thus obtained dyeings have good fastness properties.
The invention further provides a substrate which has been dyed or printed with a compound of the present invention. The substrate may be selected from any of the above mentioned substrates. A preferred substrate is a substrate comprising cellulose such as cotton or paper or paper based product.
The invention further provides a preferred process of dyeing paper comprising the continuous introduction into a stock solution which is being constantly agitated, of a dye of the present invention.
The invention yet further provides the use of a compound of the present invention for dyeing or printing any of the abovementioned substrates.
The following Examples further serve to illustrate the invention. In the Examples all parts and all percentages are by weight and the temperatures given are in degrees Celsius, unless indicated to the contrary. Parts of weight relate to parts by volume as g to ml.